Before We discuss any further, You need to have Windows Azure account and enable Windows Azure Preview features. You need a x.509 v3 certificate to register your servers with backup vaults. The certificate must have 2048 key length , have valid Client Authentication EKU, validity period is no more than 3 years and reside at certificate personal store. You can use self-signed certificate or valid SSL certificate issued by CA that is trusted and distributed by Microsoft.
Self Signed Certificate
You can use makecert.exe to create your own self-signed certificate. Visual Studio has this tool and You can use below command on Visual Studio Command Prompt
Create Backup Vault on Azure
Go to Azure Management Portal. Click the big + sign on the bottom left of the screen select Data Services>Recovery Services>Backup Vault>Quick Create. Give your vault a name and select the location.
Highlight the vault you just created > Dashboard> Download Agent > Install the agent for your environment > Follow the wizard. Currently the backup can backup these environments Windows Server 2012, Windows Server 2012 Essentials, or System Center 2012 Data Protection Manager
Upload .Cer of your certificate which You created or prepared above via Azure Management Portal. Highlight the vault > Manage Certificate > Browse .cer certificate > Upload. Next, upload the .pfx certificate to the local machine where you installed the agent. Details on Technet.
Backup the server
You need to register the servers with Windows Azure, and then you can begin manage your backups. When you installed the backup agent, it also created a Windows Azure Backup application that you will use to configure your backups, and recover your data.
Start > Launch Windows Azure Backup or on Server 2012 Dashboard > Tools > Computer Management > Windows Azure Backup. Click Register Server > You can choose to register proxy server > Create Passphrase to encrypt the traffic > Choose the location where You save passphrase.txt > Done and You can start scheduling your Backup.